Exhauster for dry-pipe systems



Nov. 20, 1923 l,474,915

G. u. RocKwooD EXHAUSTER FOR DRYv PIPE SYSTEMS Original Filed July 29. 1920 "30 central section.

Patented Nav. 2o; 1923.

UNITED ,STATES PATENT oFFicE..

GEORGE 1. Rockwool), or WORCESTER, MASSACHUSETTS.

EXHAUSTER Foa DRY-mma- SYSTEMS.

Application led 4July 29, V1920, Serial No. 399,776. Renewed April 23, 1928.

the time it takesthe water .to ieachthe.

sprinkler head that is` opened. TheA other objects of the invention Aare ychiefly to provide means adapted to be set in operationby i a slight decrease in thel air` pressure inthe risery for opening a valve to permit rapid' escape of the ,air therefrom; to provide automatic means for preventing the escape of the water through the air outlet pipe; to provide A:2D-.for preventlng the retention of Water anywhere inthe operating partsinsuch a way as to interfere with the operation thereofon account of rust or the like; and to provide effective andsimplemechanism for carrying out these` Various` functions.

Reference is to be had to the, accompanying'drawing .whicliis ,an elevation of andry pipe valve with a .preferred embodiment of this inventionl applied thereto and Shownin The invention isishown asv appliedto a dry Apipe .ralveasinglf connected at' .the

\ 1s. `well known f ySystems .in.Wl'lichttlle` riser. normally is provided .with fair ulndera, small .pressure as, l *forl ,Xam',le 50,y pounds. o, The various j, sprinkler` eadsf are all; connected;I withf the 0 riser.. When lone of them is opened rt allows their @essere Whh reducesthe air. pres l.Necessarily `the,opening ofbut a single head allowsiheainto escapey somewhat.

slowly and it' takesquitea little time for enough air to escape to reduce the pressure fot-her light articles, li

sufliciently to open the dry pipe valve. This has always been a defect ofV this type of Sprinkler System.` Another objection lies in the fact! ,that the air coming from the sprinkler head is forced out under Such a high pressure that its inuence is felt at a considerable distancev from it. There is always dangerv that apers, sawdust, and

iiely to be the first to catch fire, may be in the vicinity of the sprinkler lhead that is opened. They are likely, therefore, to be blown around and thus spread the tire.

As stated above, this invention has for its main.object the provision of means for exhaustinV the air vfrom the riser, at a point remote rom 'the fire and more rapidly than can be done through a single sprinkler head or even any number of them that are likely to'be opened at the same time when the lire starts. It also involves, in addition to the objects above mentioned, the arrangement of the parts for this purpose in such a way as to insure the system against wastage of water while in operation, and to prevent the exhaustiony of theJ air from the riserl by operating prematurely `when the sprinkler headsare all closed.

I have shown the riseras provided,.pref erably at: the. top of the system, with an exhaust pipe 15 connected with avalve casing16.This has a valve seat l'lthrough which l'the air from 'the riser Veanbe ex.-

hausted.A Iprovide 4a valve18 for this seat ,Y

ywith anspring .19 surrounding its stem and pressing on adisc 20.or,normally,holding this, valve open.V Thus,.th e ail', from the riser communicates .with`- the, artsof the valve g casing 16 located. beyond) 20 is located on,a diaphragm 2,1 in acasing 22. l ,Theair ISpace23. under this diaphragm connected by a v pipe. 24,. .which .may fhtw@ adrip valve Q5, .with the intermediate chainber2of an ordinaryldrypipe valve.v vThis l chamber, as fis wellvknown, issealedffby the valvezll, whenthat isy closed, sowtvhat the pipe2-l iscut ofi" from any pressure of the water System., @When .the main valve `13 ico opens the water .under pressure v:from the 1 water system has free access to the lower. end of the `pipe 24 and will closethevalve 18 for 1a ,purpose to be described hereinafter. l` alsow provide. means whereby lthewater pressurelwill not be transmitted too quickly to the diaphragm. This is shown in the form of a restricted inlet 27 to the pipe 24. The design of the valve18 and its mountingsv also assist this object, inasmuch as the trapped air under the diaphragm must be compressed to a sufficient pressure to overcome the reaction of the spring 19 and the system air pressure on the valve 1 8 holding its lower face against the seat 60.

The valve casing 16 is also rovided with another valve seat 30 normali;Y closed by a valve 31. having a spring 32 behind it for that purpose. Under this valve seat and 'in position to receive the air or water from the pipe 15 is a chamber 33 which may conveniently constitute a part of the valve casing 16. Its bottom is closed by a member 34 screwed into it and having a pesage` through it which constitutes a guide for a striker 35. The member 34 has an enclosed portion extending downwardly through which the striker passes and at the bottom is provided with a cap 36 having a port 37 through which the end of thestriker protrudes. A spring 38 rests on thiscap and presses upon a flange 39 on the striker. T e chamber 33 has an outlet 40.

y The bottom end of the striker is pivotally connected with a lever 42 the outer end of which rests on the top of an arm 43 which constitutes part of a lever 44. The end of this lever 44 is operated by a pair of pneumatic diaphragms 47 and 48. -It is shown as restingin a. groove in a, block 46 against the opposite parallel sides of which the two diaphragms are tightly bolted. These diaphragms consitute the bottom and top of an annular casing 49 to the flanges of which are fixed a hollow cap 50 and an air chamber 51, one above and the other below. These six parts,46,47 48,49, 50, and

- 51, are bolted together and are hermeticall'y sealed, except as to the interior of 49. They are shown as being fixedly connected with the member 34 by an arm 52. The air chamber 51 is air tight, but is.l provided with a drip valve 53 for an obvious purpose. The

air space in the cap 50 above the diaphragm v 48 communicates with the interior of the valve lcasing 16 through a pipe 54.

TheJ two diaphragms 47 and 48 are held constantly at the same distance apart by the block 46, the Weight of which tends to depress them, and the pressure of the air in the riser is communicated normally to the chamber in the cap 50 to hold the block 46 down. However, this double diaphragm arrangement has a balanced air pressure on it under normal conditions and then is held down by gravit A balanced air pressure on the two diap ragms 47 and 48 is secured by providing a small passage 56 through the lock 46 so restricted that although the chambers 50 and 51 thus communicate freelv through this passage, it prevents instantaneous equalizing of the air pressure in each when, for any reason, they become materially unbalanced.

The operation of the device will now be explained. Under operating conditions the parts are in theJ position illustrated and the dry pipe valve proper 13 is closed. If ire opens a sprinkler head the pressure in the riser is soon slightly reduced. This reduction is communicated immediately to the chamber 50, but it takes a longer time for the pressure in the chamber 51 to decrease to the vsame extent, owing to the small size of the restricted air passage 56, and as the pressure below ldiaphragm 47 now over balances that above 48 the block will rise. This takes up with it the inner end of the lever 44 and swings outwardly the arm 43 that held the striker down through .the lever 42.

`The ,spring 38 which is designed to exert a much more powerful force than the combined resista-nce of the spring 32' added to the system air pressure on the back of the valve 31, is now at liberty to force the striker up. This action immediate-ly takes place and opens the valve 31, thus giving a free exit to the air in the riser through the pipes 15 and 40. The result of this is both to exhaust the contained air in thesystem to a safe place and to open the main dry pipe valve much sooner than it would have opened without this mechanism.

When by the foregoing opera-tion the main valve has opened, water flows into the'riser and toward the sprinkler heads and 'also into the pipe 15. But before it arrivesa-t pipe 15 the water has passed through'the lpipe 24 and raised the air pressure under diaphragm 20, thereby closing the valve 18 and sealing the system. The restricted inlet prevents this action taking place before air contained in the riser has had an opportunity to escape through pipe 15.

It is desirable to exhaust all the air in the system possible before closing this valve. Therefore to get the full benefits of the invention in respect of exhausting as much of the air in the system as possible before water actually wastes through pipe 15 it is necessary to select such a volume in pipe 24 and casing 23, together with such a weight of valve 18, 'unbalanced air pressure -on valve, and stiffness of spring 19, as Willjust permit the elapse of the time required to accumulate sufficient pressure under' diaphragm 21 to close valve 18 before water ascending the riser reaches pipe 15.

After the valve 18 has beenfshut the air pressure in all chambers of the deviceexcept 23 falls to that ofthe atmosphere. Then gravity Will restore the -block 46 to the position shown provided thelever 42is raised, by hander otherwise, to permit of this motion.' The striker 35- is thus locked in the-position showniand .the valve 31 closes. When`r the fire is vunder control the/main valve 11 is closed and the water in the sys- 'usual way. The airor water in pipe 24 is allowed to escape by opening the drip valve 25 which is then closed. In Athis way lall the parts are restored to the position shown in the drawing.

It is to be observed that in addition to the effective operation above described, several contingencies are provided vfor'by the mechanism shown. For example, there is no stuffing box around the striker 35., but

l only a loose fitting guide; Therefore, any

water that escapes into the chamber 33 is free to find its exit through port 37. The entrance of the air'under pressure into the chamber 50 will not disturb the relationship of the parts connected therewith because they are already restored to normal position first. The stem of the valve 18 is guided loosel through the opening.

Although I have illustrated and described only a single form of the invention and shown it as applied only to a specific type of dry valve, I am .aware of the fact that numerous modifications can be made in the construction and relative arrangements of the mechanism, and that it can be applied to other types of dry pipe valves without A departing from the scope of the invention as expressed in the claims. Therefore I do not wish to be limited to the details of construction or specific form of dry pipe valve herein shown and described, but what I claim is Y 1. In a dry pipe valve system, the combination with the dry pipe valve, a. main for -by theaction thereof, for releasing to the atmosphere the air under higher pressure in the riser when its pressure vhas been -slightly reduced byl the' opening of one or more` sprinkler heads.

' 2. In a dry pipe valve system, the combination with the dry pipe valve, a water main, for supplying water under pressure thereto, and a riser normally containing air under a lower pressure, of an air chamber, a double diaphragm closing one end of the air chamber, the other side of said diaphragm communicating freely with said riser to place a pressure equal to the pressure 1n the riser on Y one sideof the diaphragm, means for allow,

ing leakage constantly from one side of the diaphragm to the other to balancethe dial phragm normally, and means, operated by the action of said diaphragm, for releasing the pressure in the riser when that pressure is slightly reduced.

3. In a dry pipe valve system, the combination with the dry pipe valve, a main for supplying water thereto, and a riser containing air, f a closed air chamber, a second air chamber connected with the riser and normally having the same pressure, means forpermitting'restricted leakage between said two air chambers, and means whereby a slight reduction of pressure in the chamber connected with the riser will open the riser to the atmosphere and allow the air in the riser to escape rapidly therefrom.

4.-. The combination with a dry pipe valve system, having a riser normally containing air under pressure, of a. closed air chamber, a second air chamber connected with the riser and therefore having the same pressure, means for permitting leakage between said two chambers, a valve normally preventing the escape of air from said riser, a device for positively opening said valve, means for operating said device, and means normally held in position to prevent the`action of said means when the pressures in said two chambers are equal and arranged to release said means when the pressure in the said closed air chamber is greater than a diaphragm closing one end of the air chamber, the other side of said diaphragm communicating' freely -with said riser to place a pressure equal to the pressure in the riser on one side of the diaphragm, means for allowing leakage constantly from one side of the diaphragm-to the other to balance theI diaphragm normally, a lever, a locking device connected with the diaphragm and operated thereby to hold the lever locked, a striker connected with the lever, an air release valve and means adapted to be released bythe unlocking of said striker for forcing the striker into a position to open the valve.

.6. The combination with the air riser of a dry pipe valve system, ofen air chamber, a pneumatic closing one end of the air chamber, the other side of said pneumatic communicating freely with said riserrto place a pressure equal to the pressure in the riser on one side of the pneumatlc, means for allowing leakage constantly fromone side of the pneumatic to the other to balance it norv mally, a lever, a locking device connected with the pneumatic and operated thereby to hold the lever locked normally, an air release valve a striker connected with the le- `ver, and means adapted to be released by the unlocking of said striker 'for moving'the striker into a posxtlon to open thevalve, a chamber lnto which the air from the riser is guide for the striker throufrh which any wa ter collected in said chamber is free to escape.

. 7. In a dry pipe valve system, the combination with the dry pipe valve and the riser, of means communicating therewith for opening the riser to the atmosphere upon a slight reduction of pressure therein, a second vvalve' held normally open, and means connectedwith the dry pipe valve for clos-4 ing the open valve when the dry pipe valve opens.'

8. In a dry pipe valve system, the combination with the dry pipe -va-lve, a water main for supplying water under pressure thereto, and ak r'ser normally containing air under a lower pressure, of means communieating with the riser for opening the riser to the atmosphere upon a slight reduction of pressure in the riser, a second valve adapted to be held normally open by the combined action of gravity and pressure lin said riser, and means connected with thedry pipe valve for closing the open "valve when the dry pipe valve opens, said means being restricted to prevent premature closing of said second valve.

9. In a dry pipe valve system, .thecoinbination with the dry pipe valve having anintermediate chamber, and a riser normally containing air under pressure, of a pipe connected with the riser, a valve normall closingl said pipe, means also connected wlth the riser for positively opening'saidvalve and allowing the escape of air from said pipe when the pressure in the riser is reduced, a pipe connected with the intermediate chamber in the dry pipe valve and normally protected from air or water under pressure by said valve when closed but adapted to be opcnto communication with Water under lpressure when the dry pipe valve opens. A

pneumatic device connected with the last named pipe and arranged to be raised when the pressure is introduced into the same, a valve connected with said pneumatic and adapted to be closed thereby to close the first named pipe, and means for normally holding the last named valve open.

l0. In a dry pipe valve system, the combi- Y nation with the dry pipe valve, a water main orsupplying water under pressure thereto, and a riser normally, containing airl .dry pipe valve, and normally disconnected from'said Water main by said valve when closed, but adapted to be opened thereto when the dry pipe valve opens to admit the water-from the-system into said pipe,- a diaphragm .connected with said pipe to be raised when pressure is applied from the watermain, a valve connected with said dia phragm adapted to be closed thereby, and a spring for normally holding the last named valve open.

' 11. In a dry pipe `system, the combination with an air chamber, an inlet connection to said chamber from said pipe system, said chamber also having an exhaust opening, a valve for-closing said exhaust opening, and means to open and clOSe said valve, of a second air chamber, said valve being opened b v means of excess air pressure in said second chamber and permitting the escape of the air from the System and being adapted to be closed upon the occurrence of excess air pressure in the first named chamber.

In testimony whereof I have hereunto affixed my signature.

GEORGE I. nocKwooD. 

